The present invention relates to a conveying device for conveying a fluid stream and also to a process for maintaining a conveying device of such a type. The invention further relates to an aircraft system—designed, in particular, in the form of an aircraft cooling system or aircraft air-conditioning unit—that is equipped with a conveying device of such a type.
A plurality of conveying devices for transporting a medium are integrated within a modern passenger aircraft. In an aircraft air-conditioning unit, use is made of conveying devices—designed, for example, in the form of speed-controlled fans—for conveying recirculation air out of an air-conditioned region of the aircraft into a mixer of the air-conditioning unit. A recirculation system of an aircraft air-conditioning unit that comprises a plurality of fans is described in DE 10 2008 035 122 B4 and US 2011/171896 A1, for example. Conventionally, an aircraft air-conditioning unit further includes fans which provide conditioned air for a passenger cabin, for a freight compartment or for a cockpit at the site of their use. Further conveying devices are employed in various cooling and ventilating systems for the purpose of conveying a fluid stream.